Preferred method for constructing/installing larger built-in cabinets.

Howdy Ya'll,

I am planning on putting together some large floor to ceiling cabinets to sit on either side of a trundle bed. The dimension for each cabinet will be 26" wide x 96" tall x 40" deep out of 3/4" ply. The cabinets will be tucked in either corner of the room so one side and the back will have support from the wall, and the lower third of the other side will be supported by the trundle.

This will be my first go at building carcasses this large and wondering if there are any special considerations when it comes to install and keeping them square in the long run.

I'm confident in my ability to overbuild things, but I am trying to avoid that, just for the sake of weight and material usage.

Some aspects I've been mulling over:

* Normally I use 1/4" ply for my back panels, should I plan on bracing the back or use 1/2" instead? * Should I have one fixed shelf somewhere in the middle for structure? If I wanted all adjustable shelving, what would be the best way get that structure back. * Best method of securing to the wall? Just drive screws through the cabinet into studs and patch over? Toe kick will go in first, leveled/screwed into place, and then cabinet will go on top. * Am I over thinking this?

I'm sure there are other things I'm missing, really what I'm looking for is how you cabinetry guys build/install stuff this size.

Thanks in advance!